I had seen this before and remembered that the extra dollar didn't exist but couldn't remember the explanation, so I did a search and found this from a UCSD math club post.
The extra dollar does not exist. The men paid $27 for the room, but the $2 the bellboy kept is included in that $27. The remaining $3 is in the pockets of the 3 men, so:
3 men: $ 3
Bellboy: $ 2